The club fungi are placed in the phylum Basidiomycota?

Question

a. because of their social nature

b. because they form basidia

c. because of the presence of an ascocarp

d. because they are dikaryotic

Answer 1

b.  they form basidomycetes which are the fruiting structure associated with reproduction for the basidiomycota.  

As far as social nature, these type of mushrooms are the ones you see on lawns with a working sprinkler system.